[zhuh
nuh se kwa] 
| an indefinable, elusive quality, esp. a pleasing one: She has a certain je ne sais quoi that charms everybody. |
| je ne sais quoi (zhə' nə sā kwä', sě) n. A quality or attribute that is difficult to describe or express: "Fishing has lacked a certain je ne sais quoi in terms of its public image, as all activities must that involve beer, worms and one-size-fits-all gimme caps" (Charles Leerhsen). [French : je, I + ne, not + sais : first person present indicative of savoir, to know + quoi, what.] |
That little something; a quality that eludes description: “The Mona Lisa's smile has a certain je ne sais quoi.” From French, meaning “I don't know what.”
"[T]hey are troubled with the je-ne-scay-quoy, that faign themselves sick out of niceness but know not where their own grief lies, or what ayls them." [Thomas Blount, "Glossographia," 1656]